Hi all,
I'm [trying to] develop a system that uses plug-ins to implement a
"black-box" ADT, that is a data-type and a few typeclass instances
for it. I want my system (a theorem prover) to be able to work with
any of these plug-ins (which define a logic and operations on its
formulae) but have been having trouble.
I've had a go at using forall's, and at adding a type variable
(constrained to the appropriate class) to the interface of the plug-
in, but I haven't been able to get it to work and have run out of ideas.
Is it possible to define data-types in a module loaded at run-time
with hs-plugins and have values pass out of the plug-in (though only
being used by functions within it)? Can someone point me in the right
direction?
Cheers,
Thomas Sutton